Net Primary Productivity (NPP) is one of the important biophysical variables of vegetation activity, and it plays an important role in studying global carbon cycle, carbon source and sink of ecosystem, and spatial and...Net Primary Productivity (NPP) is one of the important biophysical variables of vegetation activity, and it plays an important role in studying global carbon cycle, carbon source and sink of ecosystem, and spatial and temporal distri- bution of CO2. Remote sensing can provide broad view quickly, timely and multi-temporally, which makes it an attractive and powerful tool for studying ecosystem primary productivity, at scales ranging from local to global. This paper aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) data to estimate and analyze spatial and temporal dis- tribution of NPP of the northern Hebei Province in 2001 based on Carnegie-Ames-Stanford Approach (CASA) model. The spatial distribution of Absorbed Photosynthetically Active Radiation (APAR) of vegetation and light use efficiency in three geographical subregions, that is, Bashang Plateau Region, Basin Region in the northwestern Hebei Province and Yanshan Mountainous Region in the Northern Hebei Province were analyzed, and total NPP spatial distribution of the study area in 2001 was discussed. Based on 16-day MODIS Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) product, 16-day composite NPP dynamics were calculated using CASA model; the seasonal dy- namics of vegetation NPP in three subregions were also analyzed. Result reveals that the total NPP of the study area in 2001 was 25.1877×106gC/(m2·a), and NPP in 2001 ranged from 2 to 608gC/(m2·a), with an average of 337.516gC/(m2·a). NPP of the study area in 2001 accumulated mainly from May to September (DOY 129–272), high NPP values appeared from June to August (DOY 177–204), and the maximum NPP appeared from late July to mid-August (DOY 209–224).展开更多
以陕西省为研究对象,运用遥感和GIS手段,结合MODIS/NDVI数据、气象数据以及植被类型数据,应用CASA模型估算得到陕西省2013年的NPP数据。结果表明,2013年陕西省NPP总量为8.87×107g C/a,平均值为469.58 g C/(m2·a),NPP最高值为7...以陕西省为研究对象,运用遥感和GIS手段,结合MODIS/NDVI数据、气象数据以及植被类型数据,应用CASA模型估算得到陕西省2013年的NPP数据。结果表明,2013年陕西省NPP总量为8.87×107g C/a,平均值为469.58 g C/(m2·a),NPP最高值为723.06 g C/(m2·a),其空间分布特点表现为显著的纬度分布,南高北低,陕南>关中>陕北;NPP时间分布表现为明显的季节变化,呈单峰型曲线;植被类型NPP表现为阔叶林>针叶林>耕地>草地,并且各植被类型最大值出现月份不一致。展开更多
基金Under the auspices of the National Natural Science Foundation of China (No. 40571117), the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX3-SW-338), Research foundation of the State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences (KQ060006)
文摘Net Primary Productivity (NPP) is one of the important biophysical variables of vegetation activity, and it plays an important role in studying global carbon cycle, carbon source and sink of ecosystem, and spatial and temporal distri- bution of CO2. Remote sensing can provide broad view quickly, timely and multi-temporally, which makes it an attractive and powerful tool for studying ecosystem primary productivity, at scales ranging from local to global. This paper aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) data to estimate and analyze spatial and temporal dis- tribution of NPP of the northern Hebei Province in 2001 based on Carnegie-Ames-Stanford Approach (CASA) model. The spatial distribution of Absorbed Photosynthetically Active Radiation (APAR) of vegetation and light use efficiency in three geographical subregions, that is, Bashang Plateau Region, Basin Region in the northwestern Hebei Province and Yanshan Mountainous Region in the Northern Hebei Province were analyzed, and total NPP spatial distribution of the study area in 2001 was discussed. Based on 16-day MODIS Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) product, 16-day composite NPP dynamics were calculated using CASA model; the seasonal dy- namics of vegetation NPP in three subregions were also analyzed. Result reveals that the total NPP of the study area in 2001 was 25.1877×106gC/(m2·a), and NPP in 2001 ranged from 2 to 608gC/(m2·a), with an average of 337.516gC/(m2·a). NPP of the study area in 2001 accumulated mainly from May to September (DOY 129–272), high NPP values appeared from June to August (DOY 177–204), and the maximum NPP appeared from late July to mid-August (DOY 209–224).
文摘植被净初级生产力(net primary productivity,NPP)及其对气候变化的响应研究是全球变化的核心内容之一。通过改进的光能利用率模型(CASA模型),利用MODIS NDVI数据、土地覆盖分类数据、气象数据等,逐像元模拟2001-2010年内蒙古草地生态系统NPP的时空变化,分析其对气候因子变化的响应关系。结果表明,1)2001-2010年内蒙古草地多年平均NPP为281.3 g C/(m2.a),空间分布呈由西南向东北递增的趋势,草甸草原、典型草原和荒漠草原平均NPP分别为431.8,288.7和123.5 g C/(m2.a);2)2001-2010年间内蒙古草地NPP总体上呈上升趋势。NPP上升趋势最明显的草地主要分布在毛乌素沙地、浑善达克沙地、科尔沁沙地、呼伦贝尔盟和大兴安岭南麓地区,而下降趋势最明显的草地主要分布在阴山山脉和锡林郭勒盟中部的典型草原区;3)总体而言,降水量是内蒙古草地净初级生产力的主要影响因素。草甸草原NPP与降水量、温度的关系均很密切,而且与温度的相关性更强;典型草原和荒漠草原NPP则主要受降水量控制,其中荒漠草原NPP与降水量的关系更密切。
文摘以陕西省为研究对象,运用遥感和GIS手段,结合MODIS/NDVI数据、气象数据以及植被类型数据,应用CASA模型估算得到陕西省2013年的NPP数据。结果表明,2013年陕西省NPP总量为8.87×107g C/a,平均值为469.58 g C/(m2·a),NPP最高值为723.06 g C/(m2·a),其空间分布特点表现为显著的纬度分布,南高北低,陕南>关中>陕北;NPP时间分布表现为明显的季节变化,呈单峰型曲线;植被类型NPP表现为阔叶林>针叶林>耕地>草地,并且各植被类型最大值出现月份不一致。
